Polycarbonate compositions

ABSTRACT

This invention relates to polycarbonate compositions comprising: (A) at least one polycarbonate comprising repeating units derived from a dihydroxyaromatic compound or a dihydroxyaliphatic compound of the formula HO—Y—OH; and (B) at least one salt prepared from the reaction of one or more acidic phosphorus-containing compounds and one or more hindered amine light stabilizers. The polycarbonate compositions exhibit improved hydrolytic stability.

RELATED APPLICATONS

This application claims priority to and the benefit of the followingapplications; U.S. Patent Ser. No. 60/439,681 filed Jan. 13, 2003,incorporated herein by reference; and U.S. patent Ser. No. 10/379,649filed Mar. 5, 2003, incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to a polymer composition comprising (A) at leastone polycarbonate; and (B) one or more salts composed of at least onesuitable phosphorus-containing acid and at least one suitable hinderedamine light stabilizer.

BACKGROUND OF THE INVENTION

Hydrolytic stability is a physical characteristic commonly sought inpolymers. It is therefore desirable to find methods for providingpolymer compositions with greater hydrolytic stability and that are lessdetrimental to process equipment.

U.S. Pat. No. 4,619,956 discloses the combination of2,2,6,6-tetraalkylpiperidine hindered amine light stabilizers (HALS)and/or their addition salts with triazine ultraviolet absorbers forstabilizing thermoset acrylic and alkyd coatings. U.S. Pat. No.5,714,530 discloses the utility of combining non-polymeric2,2,6,6,-tetraalkylpiperidine HALS salts and/or their acid additionsalts with triazine ultraviolet light absorbers for stabilizing certainpolymer compositions. U.S. Pat. No. 6,051,164 discloses the use of apolymer stabilizing system comprising from about 50 to about 5,000 ppmof at least one ortho hydroxyl tris-aryl triazine light absorber andfrom about 500 ppm to about 1.25 percent of at least one oligomer,polymeric or high molecular weight HALS having a molecular weight of atleast about 500, wherein the weight ratio of HALS to triazine lightabsorber is from about 3:1 to about 20:1.

The detrimental effect of phosphorus-containing additives on thehydrolytic stability of polycarbonate and polycarbonate-polyester blendsis disclosed in U.S. Pat. Nos. 4,456,717, 5,354,791, 5,744,526,6,103,796, 4,393,158, and 6,107,375. Improved hydrolytic stability forpolycarbonates stabilized with phosphorus-containing compounds andsiloxanes containing oxetane groups are disclosed in U.S. Pat. No.4,456,717. Improved hydrolytic stability for polycarbonates stabilizedwith phosphorus-containing compounds and an oligomer or polymercontaining at least one pendant cyclic iminoether group per molecule isdisclosed in U.S. Pat. No. 6,107,375. Improved hydrolytic stability forpolycarbonates stabilized with phosphorus-containing compounds and anepoxy compound is disclosed in U.S. Pat. No. 4,393,158. Improvedhydrolytic stability for polycarbonate-polyester blends stabilized withphosphorus-containing compounds and a polyester having epoxyfunctionality is disclosed in U.S. Pat. No. 5,354,791. Improvedhydrolytic stability for polycarbonates stabilized withphosphorus-containing compounds and hexamethylene tetra amine isdisclosed in U.S. Pat. No. 5,744,526. Specifically, U.S. Pat. No.5,744,526 teaches the addition of the amine to stabilize the phosphiteagainst hydrolysis and consequently improving the hydrolytic stabilityof the polycarbonate composition.

This present invention relates to polycarbonates and the unexpectedimprovements in hydrolytic stability for polycarbonates containing anacidic phosphorous compound and a hindered amine light stabilizers(HALS).

SUMMARY OF THE INVENTION

We have discovered that the presence of certain salts in polycarbonatesresult in polymer compositions that exhibit improved hydrolyticstability and that are less detrimental to process equipment. The saltsuseful in the present invention are reaction products of a suitableinorganic acid, such as a phosphorous acid, with a suitable hinderedamine light stabilizers (HALS).

Thus, the present invention provides a polymer composition comprising:

-   (A) at least one polycarbonate; and-   (B) at least one salt prepared by the reaction of one or more acidic    phosphorus-containing compounds with one or more hindered amine    light stabilizers.

Another embodiment of the present invention is a polymer concentratecomprising:

-   (A) at least one polycarbonate; and-   (B) up to about 10 weight percent, preferably about 5 to 10 weight    percent based on the total weight of the polycarbonate of at least    one salt prepared by the reaction of one or more acidic    phosphorus-containing compounds and one or more hindered amine light    stabilizers.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a polymer composition comprising:

-   (A) at least one polycarbonate; and-   (B) a salt prepared by the reaction of one or more acidic    phosphorus-containing compounds with one or more hindered amine    light stabilizers, wherein the phosphorus-containing compounds are    selected from compounds having the formula:    wherein    -   R₁ and R₂ are independently selected from hydrogen,        C₁-C₂₂-alkyl, substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl,        substituted C₃-C₈-cycloalkyl, heteroaryl, and aryl;    -   n is 2 to 500; and    -   X is selected from hydrogen and hydroxy;        and wherein the hindered amine light stabilizers (HALS) selected        from compounds having the formulas:        wherein    -   R₁ and R₂ are independently selected from hydrogen,        C₁-C₂₂-alkyl, substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl,        substituted C₃-C₈-cycloalkyl, heteroaryl, and aryl;    -   R₃, R₄, R₅, and R₆ are independently selected from hydrogen,        C₁-C₂₂-alkyl, substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl,        substituted C₃-C₈-cycloalkyl, heteroaryl, aryl;    -   R₇ is selected from hydrogen, —OR₆, C₁-C₂₂-alkyl, substituted        C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substituted C₃-C₈-cycloalkyl;    -   R₈ is selected from hydrogen; C₁-C₂₂-alkyl, substituted        C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substituted C₃-C₈-cycloalkyl,        heteroaryl, aryl, —Y₁—R₁ or a succinimido group having the        formula    -   R₉ and R₁₀ are independently selected from hydrogen,        C₁-C₂₂-alkyl, substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, and        substituted C₃-C₈-cycloalkyl; R₉ and R₁₀ may collectively        represent a divalent group forming a ring with the nitrogen atom        to which they are attached, e.g., morpholino, piperidino and the        like;    -   L₁ is a divalent linking group selected from C₂-C₂₂-alkylene;        —(CH₂CH₂—Y₁)₁₋₃—CH₂CH₂—; C₃-C₈-cycloalkylene; arylene; or        —CO-L₂-OC—;    -   L₂, L₂′ and L₂″ are independently selected from C₁-C₂₂-alkylene,        arylene, —(CH₂CH₂—Y₁)₁₋₃—CH₂CH₂— and C₃-C₈-cycloalkylene;    -   Y₁ is selected from —OC(O)—, —NHC(O)—, —O—, —S—, —N(R₁)—;    -   Y₂ is selected from —O— or —N(R₁)—;    -   Z is a positive integer of up to about 20, preferably up to        about 6;    -   m1 is selected from 0 to about 10;    -   n1 is a positive integer selected from 2 to about 12;    -   R₁₁, R_(11′), R₁₂, and R_(12′) are independently selected from        hydrogen, C₁-C₂₂-alkyl, substituted C₁-C₂₂-alkyl,        C₃-C₈-cycloalkyl, substituted C₃-C₈-cycloalkyl, heteroaryl,        aryl, and radical A;    -   wherein radical A for R₁₁, R_(11′), R₁₂, and R_(12′) are        independently selected from the following structures:    -   Radical A structures wherein * designates the position of        attachment;        wherein at least one of R₁₁, R_(11′), R₁₂, and R_(12′) is an A        radical; and wherein the ratio of the number of phosphorus atoms        in the acidic phosphorus-containing compound to the number of        basic nitrogen atoms in the HALS is about 0.25 to about 2,        preferably from about 0.5 to about 1.1

The term “C₁-C₂₂-alkyl” denotes a saturated hydrocarbon radical whichcontains one to twenty-two carbons and which may be straight orbranched-chain. Such C₁-C₂₂ alkyl groups can be methyl, ethyl, propyl,butyl, pentyl, hexyl, heptyl, octyl, isopropyl, isobutyl, tertbutyl,neopentyl, 2-ethylheptyl, 2-ethylhexyl, and the like. The term“substituted C₁-C₂₂-alkyl” refers to C₁-C₂₂-alkyl radicals as describedabove which may be substituted with one or more substituents selectedfrom hydroxy, halogen, cyano, aryl, heteroaryl, C₃-C₈-cycloalkyl,substituted C₃-C₈-cycloalkyl, C₁-C₆-alkoxy, C₂-C₆ alkanoyloxy and thelike.

The term “C₃-C₈-cycloalkyl” is used to denote a cycloaliphatichydrocarbon radical containing three to eight carbon atoms. The term“substituted C₃-C₈-cycloalkyl” is used to describe a C₃-C₈-cycloalkylradical as detailed above containing at least one group selected fromC₁-C₆-alkyl, C₁-C₆-alkoxy, hydroxy, halogen, and the like.

The term “aryl” is used to denote an aromatic radical containing 6, 10or 14 carbon atoms in the conjugated aromatic ring structure and theseradicals substituted with one or more groups selected from C₁-C₆-alkyl;C₁-C₆-alkoxy; phenyl, and phenyl substituted with C₁-C₆-alkyl;C₁-C₆-alkoxy; halogen and the like; C₃-C₈-cycloalkyl; halogen; hydroxy,cyano, trifluoromethyl and the like. Typical aryl groups include phenyl,naphthyl, phenylnaphthyl, anthryl (anthracenyl) and the like. The term“heteroaryl” is used to describe conjugated cyclic radicals containingat least one hetero atom selected from sulfur, oxygen, nitrogen or acombination of these in combination with from two to about ten carbonatoms and these heteroaryl radicals substituted with the groupsmentioned above as possible substituents on the aryl radical. Typicalheteroaryl radicals include: 2- and 3-furyl, 2- and 3-thienyl, 2- and3-pyrrolyl, 2-, 3-, and 4-pyridyl, benzothiophen-2-yl;benzothiazol-2-yl, benzoxazol-2-yl, benzimidazol-2-yl,1,3,4-oxadiazol-2-yl, 1,3,4-thiadiazol-2-yl, 1,2,4-thiadiazol-5-yl,isothiazol-5-yl, imidazol-2-yl, quinolyl and the like.

The terms “C₁-C₆-alkoxy” and “C₂-C₆-alkanoyloxy” are used to representthe groups —O—C₁-C₆-alkyl and —OCOC₁-C₆-alkyl, respectively, wherein“C₁-C₆-alkyl” denotes a saturated hydrocarbon that contains 1-6 carbonatoms, which may be straight or branched-chain, and which may be furthersubstituted with one or more groups selected from halogen, methoxy,ethoxy, phenyl, hydroxy, acetyloxy and propionyloxy. The term “halogen”is used to represent fluorine, chlorine, bromine, and iodine; however,chlorine and bromine are preferred.

The term “C₂-C₂₂-alkylene” is used to denote a divalent hydrocarbonradical that contains from two to twenty-two carbons and which may bestraight or branched chain and which may be substituted with one or moresubstituents selected from hydroxy, halogen, C₁-C₆-alkoxy,C₂-C₆-alkanolyloxy and aryl. The term “C₃-C₈-cycloalkylene” is used todenote divalent cycloaliphatic radicals containing three to eight carbonatoms and these are optionally substituted with one or more C₁-C₆-alkylgroups. The term “arylene” is used to denote 1,2-, 1,3-, and1,4-phenylene radicals and these optionally substituted withC₁-C₆-alkyl, C₁-C₆-alkoxy and halogen.

The salt of component (B) of the novel compositions provided by thepresent invention may be prepared by bringing together the acidicphosphorus-containing compound and the hindered amine light stabilizerin a suitable manner. A suitable manner is any procedure that involvescontacting the acidic phosphorus-containing acid with the hindered aminelight stabilizer. For example, the acidic phosphorus-containing compoundand the hindered amine light stabilizer may be dissolved in anappropriate solvents and the solutions mixed followed by precipitationof the reaction product; mixing the phosphorus-containing acid and thehindered amine light stabilizer without solvent; and the like.

The ratio of the number of phosphorus atoms in the acidicphosphorus-containing compound to the number of basic nitrogen atoms inthe hindered amine light stabilizer may be in the range of about 0.05 toabout 2, preferably from about 0.25 to about 1.1. Compositions thatcontain a large excess of unreacted phosphorus-containing acidiccompounds may result in corrosion of process equipment duringconcentrate manufacture and have a negative effect on the hydrolyticstability of the polymer.

The salt or salts constituting component (B) of our novel compositionstypically is present in concentrations ranging from about 0.01 to about0.25 weight percent based on the total weight of the composition, i.e.,the total weight of the component (A) polycarbonate, the salt and anyadditional components present, such as stabilizers and pigments andcolorants. Concentrations of salt (B) within this range typically areeffective to improve the hydrolytic stability of polycarbonates. Theconcentration of the salt(s) preferably is about 0.05 to 0.15 weightpercent (same basis).

Although polycarbonates are not commonly made using metal catalysts, itis possible. The polycarbonate may contain metal catalyst residues in 10to 200 ppmw. Metal catalyst residues in concentrations of about 20 to100 ppmw are more typical. An addition source of metal catalysts residuemay be contributed by a polymer that is blended with the polycarbonate.For example, polyesters may contain 10 to 200 ppmw of metal catalystresidues. Corrosion of metal process equipment is an additional sourceof metal contaminants in polycarbonate component (A). For example, 304and 316 stainless steels contain manganese, chromium and nickel. Thesalts of component (B) of the invention can be used in the polycarbonatecompositions where the polycarbonates are either prepared by use ofmetal catalysts or contain metal contaminants or are blended withpolymers comprising metal catalyst residues such that improvedhydrolytic stability as well as improved color is provided to suchpolycarbonates.

The acidic phosphorus-containing compounds preferably are phosphorousacid, phosphoric acid and polyphosphoric acid, most preferablyphosphorous acid.

Examples of suitable hindered amine light stabilizers (HALS) include,but are not limited to: Cyasorb UV-3346 (Cytec Industries, CAS#90751-07-8), Cyasorb UV-3529 (Cytec Industries, CAS# 19309840-7),Cyasorb UV-3641 (Cytec Industries, CAS# 106917-30-0), Cyasorb UV-3581(Cytec Industries, CAS# 79720-19-7), Cyasorb UV-3853 (Cytec Industries,CAS# 167078-06-0), Cyasorb UV-3853S (Cytec Industries, CAS# 24860-22-8),Tinuvin 622 (Ciba Specialty Chemicals, CAS# 65447-77-0), Tinuvin 770(Ciba Specialty Chemicals, CAS# 52829-07-9), Tinuvin 144 (Ciba SpecialtyChemicals, CAS# 63843-89-0), Tinuvin 123 (Ciba Specialty Chemicals, CAS#129757-67-1), Chimassorb 944 (Ciba Specialty Chemicals, CAS#71878-19-8), Chimassorb 119 (Ciba Specialty Chemicals, CAS# 10699043-6),Chimassorb 2020 (Ciba Specialty Chemicals, CAS# 192268-64-7), Lowilite76 (Great Lakes Chemical Corp., CAS# 41556-26-7), Lowilite 62 (GreatLakes Chemical Corp., CAS# 65447-77-0), Lowilite 94 (Great LakesChemical Corp., CAS# 71878-19-8), Uvasil 299LM (Great Lakes ChemicalCorp., CAS# 182635-99-0), and Uvasil 299HM (Great Lakes Chemical Corp.,CAS# 182635-99-0), Dastib 1082 (Vocht a.s., CAS# 131290-28-3), Uvinul4049H (BASF Corp., CAS# 109423-00-9), Uvinul 4050H (BASF Corp., CAS#124172-53-8), Uvinul 5050H (BASF Corp., CAS# 199237-39-3), Mark LA 57(Asahi Denka Co., Ltd., CAS# 64022-61-3), Mark LA 52 (Asahi Denka Co.,Ltd., CAS# 91788-83-9), Mark LA 62 (Asahi Denka Co., Ltd., CAS#107119-91-5), Mark LA 67 (Asahi Denka Co., Ltd., CAS# 100631434), MarkLA 63 (Asahi Denka Co., Ltd. Co., Ltd. Co., CAS# 115055-30-6), Mark LA68 (Asahi Denka Co., Ltd., CAS# 10063144-5), Hostavin N 20 (ClariantCorp., CAS# 9507842-5), Hostavin N 24 (Clariant Corp., CAS# 85099-51-1,CAS# 85099-50-9), Hostavin N 30 (Clariant Corp., CAS# 78276-66-1),Diacetam-5 (GTPZAB Gigiena Truda, USSR, CAS# 76505-58-3), Uvasorb-HA 88(3V Sigma, CAS# 136504-96-6), Goodrite UV-3034 (BF Goodrich ChemicalCo., CAS# 71029-16-8), Goodrite UV-3150 (BF Goodrich Chemical Co., CAS#96204-36-3), Goodrite UV-3159 (BF Goodrich Chemical Co., CAS#130277-45-1), Sanduvor 3050 (Clariant Corp., CAS# 85099-51-0), SanduvorPR-31 (Clariant Corp., CAS# 147783-69-5), UV Check AM806 (Ferro Corp.,CAS# 154636-12-1), Sumisorb TM-061 (Sumitomo Chemical Company, CAS#84214-94-8), Sumisorb LS-060 (Sumitomo Chemical Company, CAS#99473-08-2), Uvasil 299 LM (Great Lakes Chemical Corp., CAS#164648-93-5), Uvasil 299 HM (Great Lakes Chemical Corp., CAS#164648-93-5), Nylostab S-EED (Clariant Corp., CAS# 42774-15-2).Additional preferred hindered amine light stabilizer may be listed inthe Plastic Additives Handbook 5^(th) Edition (Hanser GardnerPublications, Inc., Cincinnati, Ohio, USA, 2001).

Chimassorb 944 (Ciba Specialty Chemicals, CAS# 71878-19-8), CyasorbUV-3529 (Cytec Industries, CAS# 19309840-7), Chimassorb 119 (CibaSpecialty Chemicals, CAS# 106990-43-6) and Tinuvin 770 (Ciba SpecialtyChemicals, CAS# 52829-07-9) as described further herein in the Examplesand any equivalvents thereof are specific examples of the preferredhindered amine light stabilizers. Chimassorb 119® is another preferredHALS embodiment. The structure of Chimassorb 119® has previously beendisclosed also in the Journal of Materials Science 36 (2001) 4419-4431,incorporated herein by reference. The chemical name for Chimassorb 119®as disclosed in the Journal of Materials Science 36 (2001) at 4419-4431is 1,3,5-triazine-2,4,6-triamine,N,N′-1,2-ethane-diyl-bis[[[4,6-bis-[butyl-1,2,2,6,6,-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine-2-yl]amino]-3,1-propanediyl]]bis[N,N″-dibutylN,N″bis-(1,2,2,6,6,-pentamethyl-4-piperidinyl)-. A group of preferredhindered amine light stabilizers include ones having above formulas (1),(2), (3), (4), (5), (6), (7), (8), (9), (10), (11) and (12) whereinradical R₇ is hydrogen or alkyl. The most preferred are high molecularweight HALS wherein the molecular weight is greater than about 1000 suchas Cyasorb UV-3529 (Cytec Industries, CAS# 193098-40-7). The mostpreferred HALS correspond to formula (6) set forth above whereinR₃=R₄=R₅=R₆=R₇=methyl, (R₉)(R₁₀)N— collectively represent morpholino, L₁is C₁ to C₆ alkylene, and Z is 1 to 6.

The term “polycarbonate” as used herein embraces those polycarbonatescomprising repeating units or residues of the formula

wherein Y is a divalent aromatic or aliphatic radical derived from adihydroxyaromatic compound or a dihydroxyaliphatic compound of theformula HO—Y—OH. Typical dihydroxyaromatic compounds are2,2-bis-(4-hydroxyphenyl)propane, also known as bisphenol A;bis(4-hydroxyphenyl)methane; 2,2-bis(4-hydroxy-3-methylphenyl)-propane;4,4-bis(4-hydroxyphenyl)heptane;2,2-(3,5,3′,5′-tetrachloro-4,4′-dihydroxyphenyl)propane;2,2-(3,5,3′,5′-tetrabromo-4,4′-dihydroxyphenol)propane;3,3′-dichloro-3,3′-dichloro-4,4′-dihydroxydiphenyl)methane;2,2′-dihydroxyphenylsulfone, and 2,2′-dihydroxylphenylsulfide. Mostpreferably, HO—Y—OH is 2,2-bis-(4-hydroxyphenyl)propyl, in which case,the polycarbonate is a “bisphenol A polycarbonate”. Examples ofdihydroxyaliphatic compounds include 1,4-cyclohexanedimethanol,1,2-propanediol, 1,3-propanediol, 1,4-butanediol,2,2-dimethyl-1,3-propanediol, 1,6-hexanediol,2,6-decahydronaphthalenedimethanol, 1,2-cyclohexanediol,1,4-cyclohexanediol, 1,2-cyclohexanedimethanol,1,3-cyclohexanedimethanol, isosorbide,4,4′-isopropylidenedicyclohexanol,2,2,4,4-tetramethylcyclobutane-1,2-diol,Z,8-bis(hydroxymethyl)-tricyclo-[5.2.1.0]-decane wherein Z represents 3,4, or 5; and diols containing one or more oxygen atoms in the chain,e.g., diethylene glycol, triethylene glycol, dipropylene glycol,tripropylene glycol and the like. In general, these diols contain 2 to18, preferably 2 to 8 carbon atoms. Cycloaliphatic diols can be employedin their cis or trans configuration or as mixtures of both forms.Branched polycarbonates are also useful in the present invention.

The polycarbonates comprising component (A) of the above-describedembodiment of the present invention may be prepared according to knownprocedures by reacting the dihydroxyaromatic compound with a carbonateprecursor such as phosgene, a haloformate or a carbonate ester, amolecular weight regulator, an acid acceptor and a catalyst. Methods forpreparing polycarbonates are known in the art and are described, forexample, in U.S. Pat. No. 4,452,933, which is hereby incorporated byreference herein.

Examples of suitable carbonate precursors include carbonyl bromide,carbonyl chloride, and mixtures thereof; diphenyl carbonate; adi(halophenyl)carbonate, e.g., di(trichlorophenyl) carbonate,di(tribromophenyl) carbonate, and the like; di(alkylphenyl)carbonate,e.g., di(tolyl)carbonate; di(naphthyl)carbonate;di(chloronaphthyl)carbonate, or mixtures thereof; and bis-haloformatesof dihydric phenols.

Examples of suitable molecular weight regulators include phenol,cyclohexanol, methanol, alkylated phenols, such as octylphenol,para-tertiary-butylphenol, and the like. The preferred molecular weightregulator is phenol or an alkylated phenol.

The acid acceptor may be either an organic or an inorganic acidacceptor. A suitable organic acid acceptor is a tertiary amine andincludes such materials as pyridine, triethylamine, dimethylaniline,tributylamine, and the like. The inorganic acid acceptor can be either ahydroxide, a carbonate, a bicarbonate, or a phosphate of an alkali oralkaline earth metal.

The catalysts that can be used are those that typically aid thepolymerization of the monomer with phosgene. Suitable catalysts includetertiary amines such as triethylamine, tripropylamine,N,N-dimethylaniline, quanternary ammonium compounds such as, forexample, tetraethylammonium bromide, cetyl triethyl ammonium bromide,tetra-n-heptylammonium iodide, tetra-n-propyl ammonium bromide,tetramethyl ammonium chloride, tetra-methyl ammonium hydroxide,tetra-n-butyl ammonium iodide, benzyltrimethyl ammonium chloride andquaternary phosphonium compounds such as, for example, n-butyltriphenylphosphonium bromide and methyltriphenyl phosphonium bromide.

The polycarbonate of component (A) also may be a copolyestercarbonatesuch as those described in U.S. Pat. Nos. 3,169,121; 3,207,814;4,194,038; 4,156,069; 4,430,484, 4,465,820, and 4,981,898, all of whichare incorporated by reference herein.

Copolyestercarbonates useful in this invention are availablecommercially. They are typically obtained by the reaction of at leastone dihydroxyaromatic compound with a mixture of phosgene and at leastone dicarboxylic acid chloride, especially isophthaloyl chloride,terephthaloyl chloride, or both.

The present invention provides polycarbonates that exhibit improvedhydrolytic stability. The acidic phosphorus-containing compound salts ofsuitable hindered amine light stabilizer [Component (B)] are useful inproviding that hydrolytic stability.

Another embodiment of the present invention is a polymer concentratecomprising:

-   (A) at least one polycarbonate; and-   (B) up to about 10 weight percent, preferably about 5 to 10 weight    percent, based on the total weight of the polycarbonate of at least    one salt prepared by the reaction of one or more acidic    phosphorus-containing compounds and one or more hindered amine light    stabilizers.

The compositions of the present invention also may contain one or morecompounds selected from the group consisting of (C) water, (D) colorantsand pigments such as organic colorants, inorganic colorants and or whitepigments such as TiO₂, ZnO and baryta, (E) other additives such asimpact modifiers, plasticizers, halogenated flame-retardants, fillers,nonhalogenated flame-retardants, synergists, processing aids, phosphitestabilizers, phosphonite stabilizers and other stabilizers known to oneskilled in the art; and (F) a recycled polymer.

The terms “phosphite stabilizers” and “phosphonite stabilizers” refer tosecondary antioxidants that are known to those skilled in the art andmay be represented by the structures listed on pages 109-112 in thePlastic Additives Handbook 5^(th) Edition (Hanser Gardner Publications,Inc., Cincinnati, Ohio, USA, 2001), incorporated herein by reference inits entirety. Some common phosphite stabilizers are as follows: Ultranox626 (GE Specialty Chemicals, CAS# 26741-53-7), Irgafos 168 (CibaSpecialty Chemicals, CAS# 31570-044), Weston 619 (GE SpecialtyChemicals, CAS# 3806-34-6) and Doverphos S-9228 (Dover Chemicals, CAS#154862-43-8).

The term “halogenated flame-retardants” is defined as compounds that cancontain one or more of the following: fluorine, chlorine, bromine, andiodine, which act in such a way as to decrease the flammability of thepolymer composition. More preferred are compounds that contain brominesuch as brominated polycarbonate, brominated polystyrene, and the like.

Salts of phosphorus-containing acids and hindered amine lightstabilizers, as defined herein, may reduce the amount of corrosion toprocess equipment as compared to some of the hydrolysis products ofcommercial phosphites, phosphorous acid, phosphoric acid, andpolyphosphoric acid, thereby improving the color of the polymercomposition and improving the lifetime of the process equipment.

The compositions provided by the present invention are useful forimproving the properties of heavy-gauge sheet, cap layers for extrudedsheet, cap layers for extruded films, thermoformable sheeting products,injection molded products, thin films, thick films, articles made usingthin films, articles using from thick films, articles made using heavygauge sheet, multilayer films, twin-wall sheet, triple wall sheet andthe like.

This invention is further illustrated by the following examples ofpreferred embodiments thereof, although it will be understood that theseexamples are included merely for purposes of illustration and are notintended to limit the scope of the invention unless otherwisespecifically indicated. Unless otherwise indicated, all weightpercentages are based on the total weight of the polymer composition andall molecular weights are weight average molecular weights. Also, allpercentages are by weight unless otherwise indicated. Wherever an Rgroup, L group, Y group, Z group, m group or n group is defined herein,the definition for a particular group remains the same throughout thisdescription regardless of whether it is used for multiple formulas ortypes of compounds unless otherwise specified.

EXAMPLES

Experimental Conditions:

In the examples, the following procedures were followed. To evaluate theeffect of additives on hydrolytic stability of polycarbonate-polyesterblends, samples were cut from 20-mil film and then exposed to 70° C. and100% relative humidity by suspending the films in the vapor space ofsealed jars containing a small amount of water and placed inside aforced air oven set at 70° C. Small samples were subsequently takenperiodically and the molecular weight distribution for the polyester andpolycarbonate components determined using gel permeation chromatography(GPC). The GPC method for the polycarbonate fraction consisted of firstimmersing the blends in tetrahydrofuran to selectively extract thepolycarbonate. The GPC system used to analyze the polycarbonate fractionconsisted of a Perkin-Elmer LC-250 pump, a Perkin-Elmer LC-600autosampler, and a Perkin-Elmer LC-235 photodiode array UV detectoroperated at 265 nm. The columns used were a Plgel 5-micron guard, aMixed-C, and an Oligopore from Polymer Laboratories. The molecularweight distribution was computed using monodisperse polystyrenestandards for calibration and the Mark-Houwink constants for polystyreneand polycarbonate available in the literature. The solvent used for thepolyester fraction was 70/30-v/v hexafluoroisopropanol/methylenechloride mixture, which is also a good solvent for polycarbonate. TheGPC system used consisted of a Perkin-Elmer LC-250 pump, a Perkin-ElmerISS-200 autosampler, and a Perkin-Elmer LC-95 UV/VIS detector operatedat 285 nm. The absorption coefficient of terephthalate basedcopolyesters at 285 nm is considerably greater than the coefficient forpolycarbonate so that the method selectively detects the polyester. Thecolumns used were a Plgel 5-micron guard and a Mixed-C from PolymerLaboratories. The molecular weight distribution was computed usingmonodisperse polystyrene standards for calibration and Mark-Houwinkconstants for polystyrene measured in this solvent. Universalcalibration constants for each polyester were chosen to yield accuratemolecular weight values for a series of samples that were characterizedby light scattering measurement.

The color of the polymer films is determined in a conventional mannerusing a HunterLab UltraScan Colorimeter manufactured by HunterAssociates Laboratory, Inc., Reston, Va. The instrument is operatedusing HunterLab Universal Software (version 3.8). Calibration andoperation of the instrument is according to the HunterLab User Manualand is largely directed by the Universal Software. To reproduce theresults on any colorimeter, run the instrument according to itsinstructions and use the following testing parameters: D65 Light Source(daylight, 6500° K color temperature), Reflectance Mode, Large AreaView, Specular Included, CIE 10° Observer, Outputs are CIE L*, a*, b*.An increase in the positive b* value indicates yellowness, while adecrease in the numerical value of b* indicates a reduction inyellowness. Color measurement and practice are discussed in greaterdetail in Anni Berger-Schunn in Practical Color Measurement, Wiley, N.Y.pages 39-56 and 91-98 (1994). Preferably, for 20-mil films the b* valueis less than +0.75, more preferably from about +0.25 to about −0.25.

Examples 1-5

These examples illustrate the detrimental effect of commercial phosphitestabilizers on the hydrolytic stability of polycarbonate-polyesterblends. The polyester, polyester A, is a polyester comprised of 74 molepercent terephthalic acid residues, 26 mole percent isophthalic acidresidues and 100 mole percent 1,4-cyclohexanedimethanol residues havingan inherent viscosity of about 0.74 and containing approximately 100ppmw titanium metal and the polycarbonate, polycarbonate A, is abisphenol A polycarbonate supplied by Bayer as Makrolon 2608. Thefollowing commercial phosphites were utilized: Ultranox 626 (GESpecialty Chemicals, CAS# 26741-53-7, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite), Ultranox 641 (GE Specialty Chemicals, CAS#26741-53-7, 2,4,6-tri-tert-butylphenyl-2-butyl-2-ethyl-1,3-propanediolphosphite), Weston 619 (GE Specialty Chemicals, CAS# 3806-34-6,distearyl pentaerythritol diphosphite) and Doverphos S-9228 (DoverChemicals, CAS# 15486243-8, bis(2,4-dicumylphenyl) pentaerythritoldiphosphite). The phosphite stabilizers were precompounded withpolyester A using an 19-mm APV twin-screw extruder at 250° C., 200 RPM,at a rate of about 5 lbs/hr to produce concentrates containing 5 percentphosphite stabilizer. Blends of polyester A and polycarbonate A wereprepared by melt blending a 3:1 weight ratio of polyester A withpolycarbonate A, respectively, with 0.5 weight percent of the variousphosphite stabilizers as reported in Table 1. The blends were preparedas 20-mil extrusion cast films using a 1″ Killion single-screw extruderat 275° C. and 70 RPM. The films were subsequently conditioned at 70° C.and 100% relative humidity for up to 3 weeks and the molecular weight ofthe polyester A and polycarbonate A components determined by GPC aspreviously described. The results are shown in Table 1. As shown inTable 1, the addition of a phosphite stabilizer improves the blend color(i.e. less yellow as represented by lower b*); however, the phosphitesare detrimental to hydrolytic stability of the blend as indicated bysignificant decrease in molecular weight for both the polyester A andpolycarbonate A components. TABLE 1 20-mil Hydrolytic Stability @ 70° C.and 100% Relative Humidity CIE Exposure polyester A polyester Apolycarbonate A polycarbonate A Example Phosphite b* (weeks) Mw ΔMw (%)Mw ΔMw (%) 1 No 9.6 0 23297 0.0 13582 0.0 Stabilizer 1 23595 1.3 12446−8.4 2 23408 0.5 14007 3.1 3 23528 1.0 13391 −1.4 2 Weston −0.1 0 231230.0 20723 0.0 619 1 21337 −7.7 14339 −30.8 2 20532 −11.2 12239 −40.9 320317 −12.1 9919 −52.1 3 Ultranox 0.5 0 22559 0.0 21684 0.0 626 1 20813−7.7 14663 −32.4 2 20452 −9.3 12888 −40.6 3 20129 −10.8 11102 −48.8 4Doverphos 0.4 0 22339 0.0 20935 0.0 9228 1 20937 −6.3 14860 −29.0 220112 −10.0 13385 −36.1 3 20641 −7.6 11561 −44.8 5 Ultranox 0.6 0 226510.0 20128 0.0 641 1 21367 −5.7 12889 −36.0 2 20461 −9.7 11244 −44.1 320574 −9.2 9722 −51.7Weston 619 is distearyl pentaerythritol diphosphite.Ultranox 626 is Bis(2,4-di-t-butylphenyll) pentaerythritol diphosphite.Doverphos 9228 is Bis(2,4-dicumylphenyll) pentaerythritol diphosphite.Ultranox 641 is 2,4,6 tri-t-butylphenyl 2 butyl 2 ethyl 1,3 propane diolphosphite.

Examples 6-19 Phosphorous Acid Salts of Hindered Amine Light Stabilizers(HALS)

These examples illustrate improved hydrolytic stability forpolycarbonate-polyester blends containing phosphorous acid salts of HALScompared to blends containing phosphorous acid. The polyester, polyesterB, comprised of 100 mole percent terephthalic acid residues, 62 molepercent cyclohexandimethanol and 38 mole percent ethylene glycolresidues having an inherent viscosity of about 0.7 and thepolycarbonate, polycarbonate B, is a bisphenol A polycarbonate(tradename Makrolon 1804 (Bayer Corporation) believed to contain about0.25 wt % of a ultraviolet light absorbing compound and a blue tonercolorant. A 70:30 ratio by weight blend of polyester B and polycarbonateB (70:30 blend by weight) were melt blended with 0.03 weight percent and0.06 weight percent of phosphorous acid and the phosphorous acid saltsdescribed in Table 2. The phosphorous acid salts were compounded withpolyester B using a WP 30-mm twin-screw extruder at 250° C., 250 RPM ata rate of about 40 lbs/hr to produce concentrates containing 5 percentof the phosphorous acid salt. The polyester B and polycarbonate B blendswere subsequently prepared as 20-mil extrusion cast films using a 1″Killion single-screw extruder at 275° C. and 70 RPM.

Example 6 No Stabilizer (Comparative Example)

A blend was prepared as described previously without any addedstabilizer.

Example 7 Phosphorous Acid (Comparative Example)

A phosphorous acid concentrate was prepared by mixing pellets ofpolyester B with a 45 percent weight percent aqueous solution ofphosphorous acid and then drying under vacuum to produce a concentratecontaining 2.5 percent phosphorous acid. Blends were prepared asdescribed previously with 0.03 weight percent and 0.06 weight percentphosphorous acid.

Examples 8-10 Phosphorous Acid Salts of Cyasorb UV-3529

Phosphorous acid and Cyasorb UV-3529 (supplied by Cytec Industries,Inc.), which is a polymeric hindered amine light stabilizer (HALS)believed to conform generally to the compounds of amine formula (6) setforth above whrein R₃=R₄=R₅=R₆=R₇=methyl; L₁ is hexamethylene; and(R₉)(R₁₀)N— collectively represent a morpholino group, were added to alarge mortar and pestle according to Table 2. The solids were ground toa fine powder thereby forming a salt and placed into a vacuum ovenovernight at 70° C. with a slight ingress of dry nitrogen. The solid wasallowed to cool to room temperature and ground again to a fine powderusing mortar and pestle. Blends were prepared as described previouslywith 0.03 and 0.06 weight percent of each phosphorous acid salt. TABLE 2Example Phosphorous Acid (g) Cyasorb 3529 (g) 8 32.76 200 9 65.45 200 1098.18 200

Examples 11-14 Phosphorous Acid Salts of Chimassorb 119

Phosphorous acid and Chimassorb 119 were added to a large mortar andpestle according to Table 3. The chemical name for Chimassorb 119® asdisclosed in the Journal of Materials Science 36 (2001) at 4419-4431 is1,3,5-triazine-2,4,6-triamine,N,N′-1,2-ethane-diyl-bis[[[4,6-bis-[butyl-1,2,2,6,6,-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine-2-yl]amino]-3,1-propanediyl]]bis[N,N″-dibutylN,N″bis-(1,2,2,6,6,-pentamethyl-4-piperidinyl)-. The solids were groundto a fine powder and placed into a vacuum oven overnight at 70° C. witha slight ingress of dry nitrogen. The solid was allowed to cool to roomtemperature and ground again to a fine powder using mortar and pestle.Blends were prepared as described previously with 0.03 and 0.06 weightpercent of each phosphorous acid salt. TABLE 3 Example Phosphorous Acid(g) Chimassorb 119 (g) 11 37.19 200 12 74.38 200 13 111.57 200 14 148.76200

Example 15-17 Phosphorous Acid Salts of Tinuvin 770

To a clean dry 5 L three neck round-bottomed flask equipped with amechanical stirrer, thermocouple, heating mantle and addition funnel wasadded Tinuvin 770, as described in Table 4 and 1.5 L of isopropylalcohol. (Tinuvin 770 is a hindered amine light stabilizer believed toconform generally to the compounds of amine formula (3) set forth abovewherein R₃=R₄=R₅=R₆=methyl; R₇ is hydrogen; Y₂ is —OCO—; and L₁ isoctamethylene.) The mixture was heated to 30° C. and stirred until ahomogeneous solution was obtained. To a clean dry 2 L beaker was addedphosphorous acid as given in Table 5 and 1 L of isopropyl alcohol. Themixture was stirred until a homogeneous solution was obtained. Thephosphorous acid solution was added to the addition funnel and deliveredto the stirred reaction vessel at a rate of about 50 mL/min. A solidformed as the phosphorous acid solution was added. Stirring wascontinued at about 30° C. for 1 h upon complete addition of thephosphorous acid solution. The reaction mixture was allowed to cool toroom temperature and the product was further precipitated by adding halfof the material to each of two 4 L beakers that contained 1.5 L ofrapidly stirred heptane (equipped with a mechanical stirrer). The solidmaterial was collected by suction filtration, washed with 500 mL ofheptane, and then allowed to dry on the filter paper overnight. Thesolid cake was broken up, placed into a 12″×7″×2″ aluminum pan and driedin a vacuum oven at 70° C. at about 15 mm of Hg with a slight ingress ofdry nitrogen for 2 days. Blends were prepared as described previouslywith 0.03 and 0.06 weight percent of each phosphorous acid salt. TABLE 4Phosphorous Acid Tinuvin 770 Yield Example g (mole) g (mole) (% oftheoretical) 15 450 (0.94)  76.71 (0.94) 90 16 425 (0.88) 106.68 (1.32)97 17 400 (0.83) 143.20 (1.75) 97

Example 18 Phosphorous Acid Salt of Cyasorb UV-3346

To a clean dry 5 L three neck round-bottomed flask equipped with amechanical stirrer and addition funnel was added 200 g of CyasorbUV-3346 (HALS, supplied by Cytec Industries, Inc.) and 1 kg of toluene.Cyasorb UV-3346 is a polymeric hindered amine light stabilizer believedto conform generally to the compounds of amine formula (6) set forthabove R₃=R₄=R₅=R₆=methyl; R₇=hydrogen; L₁ is hexamethylene; and(R₉)(R₁₀)N— collectively represent a morpholino group. The mixture wasstirred until a homogeneous solution was obtained. To a clean dry 1 Lbeaker was added 30.69 g of phosphorous acid and 200 g of isopropylalcohol. The mixture was stirred until a homogeneous solution wasobtained. The phosphorous acid solution was added to the addition funneland delivered to the stirred reaction vessel at a rate of about 13mL/min. A precipitate began to form. Stirring was continued for about 30min upon complete addition of the phosphorous acid solution. Heptane (1kg) was added to the reaction mixture at a dropwise rate to precipitatethe product. The solid material was collected by suction filtration andwashed twice with 100 mL of heptane, then allowed to dry on the filterpaper overnight. The solid cake was broken up, placed into a 12″×7″×2″aluminum pan, and dried in a vacuum oven at 70° C. at about 15 mm of Hgwith a slight ingress of dry nitrogen for 24 h to give 230.05 g ofmaterial (100% of theoretical yield). Blends were prepared as describedpreviously with 0.03 and 0.06 weight percent the phosphorous acid salt.

Example 19 Phosphorous Acid Salt of Cyasorb UV-3346

To a clean dry 5 L three neck round-bottomed flask equipped with amechanical stirrer and addition funnel was added 200 g of CyasorbUV-3346, which is previously described in Example 18, and 1 kg oftoluene. The mixture was stirred until a homogeneous solution wasobtained. To a clean dry 1 L beaker was added 61.37 g of phosphorousacid and 400 g of isopropyl alcohol. The mixture was stirred until ahomogeneous solution was obtained. The phosphorous acid solution wasadded to the addition funnel and delivered to the stirred reactionvessel at a rate of about 10 mL/min. A precipitate began to form.Stirring was continued for about 30 min upon complete addition of thephosphorous acid solution. Heptane (1 kg) was added to the reactionmixture at a dropwise rate to precipitate the product. The solidmaterial was collected by suction filtration and washed twice with 100mL of heptane, then allowed to dry on the filter paper overnight. Thesolid cake was broken up, placed into a 12″×7″×2″ aluminum pan, anddried in a vacuum oven at 70° C. at about 15 mm of Hg with a slightingress of dry nitrogen for 24 h to give 259.09 g of material (100% oftheoretical yield). Blends were prepared as described previously with0.03 and 0.06 weight percent the phosphorous acid salt.

The blends described in Examples 6-19 were evaluated for hydrolyticstability at 70° C. and 100% relative humidity for up to 6 weeks asdescribed previously. The results for blends containing 0.03 and 0.06weight percent phosphorous acid salt are shown in Tables 5 and 6respectively. As shown, the addition of phosphorous acid or phosphorousacid salts of HALS dramatically improves the color (i.e. less yellow asrepresented by lower b*) of polycarbonate-polyester blends compared tothe blends without a phosphorus-containing compound (Example 6). Example7 serves to illustrate the detrimental effect of phosphorous acid on thehydrolytic stability of the blend components similar to the resultsshown previously in Examples 2-5 that contained commercial phosphitestabilizers. However, the hydrolytic stability of the blend componentsis significantly improved for the blends containing phosphorous acidsalts of HALS (Examples 8-19) compared to the blends containingphosphorous acid only (Example 7). TABLE 5 Hydrolytic Stability ofBlends with 0.03% by weight phosphorous acid salts Polyester BPolycarbonate B ΔMw ΔMw ΔMw ΔMw ΔMw ΔMw (%) (%) (%) (%) (%) (%) ExampleCIE b* Initial Mw 2 wks 4 wks 6 wks Initial Mw 2 wks 4 wks 6 wks 6 0.929111 −0.6 −0.6 −1.9 22415 −5.5 −9.2 −10.5 7 −0.1 28379 −3.0 −6.9 −11.421990 −14.3 −34.6 −37.3 8 0.2 30055 0.7 −0.3 −1.7 21453 0.9 −9.0 −12.2 9−0.1 29695 1.8 0.7 −1.6 20979 0.8 −9.3 −10.2 10 −0.1 29492 1.2 0.4 −1.922741 −10.6 −16.8 −18.9 11 0.5 30208 −1.1 −1.2 −2.1 22626 −4.8 −15.0−13.3 12 03 29089 2.3 1.8 0.1 22191 −6.7 −17.9 −17.5 13 0.2 29321 −0.2−1.5 −3.1 22220 −4.8 −19.2 −23.0 14 0.0 29067 0.2 −2.1 −4.9 22145 −10.7−20.1 −23.6 15 0.1 29486 0.5 −0.4 0.0 22370 −11.1 −20.7 −20.0 16 0.029376 1.0 0.8 −0.1 22220 −11.9 −19.4 −20.8 17 −0.1 29746 −1.3 −1.0 −2.521808 −14.3 −16.6 −30.7 18 0.1 30093 0.6 −1.0 −2.0 22463 −7.5 −14.4−17.9 19 0.1 29609 1.3 0.7 −2.3 23009 −12.2 −15.0 −17.4

TABLE 6 Hydrolytic Stability of Blends with 0.06 Weight PercentPhosphorous Acid Salts Polyester B Polycarbonate B ΔMw ΔMw ΔMw ΔMw ΔMwΔMw (%) (%) (%) (%) (%) (%) Example CIE b* Initial Mw 2 wks 4 wks 6 wksInitial Mw 2 wks 4 wks 6 wks 6 0.9 29111 −0.6 −0.6 −1.9 22415 −5.5 −9.2−10.5 7 −0.2 28477 −12.7 −19.1 −24.7 21518 −27.8 −53.1 −55.4 8 −0.229538 1.4 0.2 −0.6 21717 −6.8 −15.0 −15.3 9 −0.2 30029 0.6 −1.6 −3.022270 −4.5 −17.1 −16.2 10 −0.1 29518 1.5 0.8 −2.5 23287 −13.8 −21.7−22.2 11 0.1 29884 0.7 −1.2 −3.0 22665 −13.6 −17.2 −19.3 12 0.0 29535−0.2 −1.0 −2.9 21764 −3.5 −19.2 −19.1 13 −0.1 29351 −0.8 −2.7 −4.9 21614−9.6 −16.2 −24.8 14 −0.1 29288 −1.9 −4.8 −9.9 22072 −16.6 −27.1 −31.0 150.0 29465 0.4 −0.2 −0.4 23459 −21.4 −27.8 −31.3 16 −0.1 29269 0.9 0.6−1.2 21965 −12.1 −23.8 −29.8 17 −0.1 29189 0.8 1.2 −2.1 22114 −24.4−30.6 −33.7 18 0.1 29962 −0.4 0.2 −2.6 22278 −4.1 −12.0 −15.5 19 −0.129864 0.3 −1.3 −2.3 22057 −4.5 −9.7 −18.4

Examples 20-22 Phosphorous Acid Salts Prepared by Mechanical and OrganicMethods

These examples illustrate different methods of preparing the phosphorousacid salts. To a clean, dry 5 L three neck round-bottomed flask equippedwith a mechanical stirrer and addition funnel was added 100 g of CyasorbUV-3529, which is described in Examples 8-10, and 575 g of toluene. Themixture was stirred until a homogeneous solution was obtained. To aclean dry 2 L beaker was added 28.05 g (0.34 mol) of phosphorous acidand 575 g of isopropyl alcohol. The mixture was stirred until ahomogeneous solution was obtained. The phosphorous acid solution wasadded to the addition funnel and delivered to the stirred reactionvessel over 2 h (added dropwise). Stirring was continued for about 30min upon complete addition of the phosphorous acid solution. Thereaction product was precipitated by adding half of the reaction mixtureto each of two 4 L beakers that contained 2475 g of rapidly stirredheptane (equipped with a mechanical stirrer). The solid material wascollected by suction filtration and washed with 500 mL of heptane thenallowed to dry on the filter paper overnight. The solid cake was brokenup, placed into a 12″×7″×2″ aluminum pan and dried in a vacuum oven at70° C. at about 150 torr with a slight ingress of dry nitrogen for 24 hto give 135.07 g of material (>100% of theory, slightly solvent wet).

Blends of polyester B and polycarbonate B (70:30 blend ratio by weight)were melt blended along with 0.1 weight percent of the phosphorous acidsalt prepared by an organic method (Example 20), the phosphorous acidsalt prepared by a mechanical method described in Example 9 (Example 21)and Weston 619 (Example 22) for comparison. The phosphorous acid saltsand Weston 619 were compounded with polyester B using a 30-mm WPtwin-screw extruder at 250° C., 250 RPM at a rate of about 40 lbs/hr toproduce concentrates containing 5 percent of each additive. The blendswere prepared as 20-mil extrusion cast films using a 1″ Killionsingle-screw extruder at 275° C. and 70 RPM. The blends were evaluatedfor hydrolytic stability at 70° C. and 100% relative humidity for up to6 weeks as described previously and the results are shown in Tables 7.The results show significantly improved hydrolytic stability for theblends containing the phosphorous acid salts whether prepared by anorganic method (Example 20) or a mechanical method (Example 21) comparedto the commercial phosphite stabilizer Weston 619 (Example 22). TABLE 7Polyester A Polycarbonate A ΔMw ΔMw ΔMw ΔMw ΔMw ΔMw Initial (%) (%) (%)Initial (%) (%) (%) Example Mw 2 wks 4 wks 6 wks Mw 2 wks 4 wks 6 wks 2027105 −1.7 −3.1 7.3 23287 −8.4 −21.6 −25.5 21 26159 1.1 −0.8 7.9 22538−8.1 −18.2 −24.0 22 25957 −6.4 −9.1 −8.5 22308 −25.7 −40.3 −49.0

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

1. A polymer composition comprising: (A) at least one polycarbonate; and(B) at least one salt prepared by the reaction of one or more acidicphosphorus-containing compounds with one or more hindered amine lightstabilizers.
 2. A polymer composition according to claim 1 wherein theacidic phosphorus compounds are selected from the compounds having theformulas:

wherein R₁ and R₂ are independently selected from hydrogen,C₁-C₂₂-alkyl, substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substitutedC₃-C₈-cycloalkyl, heteroaryl, and aryl; n is 2 to 500; and X is selectedfrom hydrogen and hydroxy; and wherein the hindered amine lightstabilizers selected from compounds having the formulas:

Wherein R₁ and R₂ are independently selected from hydrogen,C₁-C₂₂-alkyl, substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substitutedC₃-C₈-cycloalkyl, heteroaryl, and aryl; R₃, R₄, R₅, and R₆ areindependently selected from hydrogen, C₁-C₂₂-alkyl, substitutedC₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substituted C₃-C₈-cycloalkyl,heteroaryl, aryl; R₇ is selected from hydrogen, —OR₆, C₁-C₂₂-alkyl,substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substitutedC₃-C₈-cycloalkyl; R₈ is selected from hydrogen; C₁-C₂₂-alkyl,substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substitutedC₃-C₈-cycloalkyl, heteroaryl, aryl, —Y₁—R₁ or a succinimido group havingthe formula

R₉ and R₁₀ are independently selected from hydrogen, C₁-C₂₂-alkyl,substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, and substitutedC₃-C₈-cycloalkyl; R₉ and R₁₀ may collectively represent a divalent groupforming a ring with the nitrogen atom to which they are attached, e.g.,morpholino, piperidino and the like; L₁ is a divalent linking groupselected from C₂-C₂₂-alkylene; —(CH₂CH₂—Y)₁₋₃—CH₂CH₂—;C₃-C₈-cycloalkylene; arylene; or —CO-L₂-OC—; L₂ is selected fromC₁-C₂₂-alkylene, arylene, —(CH₂CH₂—Y₁)₁₋₃—CH₂CH₂— andC₃-C₈-cycloalkylene; Y₁ is selected from —OC(O)—, —NHC(O)—, —O—, —S—,—N(R₁)—; Y₂ is selected from —O— or —N(R₁)—; Z is a positive integer ofup to about 20, preferably up to about 6; m1, is selected from 0 toabout 10; n1 is a positive integer selected from 2 to about 12; R₁₁, andR₁₂ are independently selected from hydrogen, C₁-C₂₂-alkyl, substitutedC₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substituted C₃-C₈-cycloalkyl,heteroaryl, aryl, and radical A wherein radical A is selected from thefollowing structures:

Radical A structures wherein * designates the position of attachment.wherein at least one of R₁₁ and R₁₂ is an A radical; and wherein theratio of the number of phosphorus atoms in the acidicphosphorus-containing compound to the number of basic nitrogen atoms inthe HALS is about 0.25 to about 2, preferably from about 0.5 to about1.1
 3. A polymer composition comprising: (A) at least one polycarbonate;and (B) about 0.01 to about 0.25 weight percent based on the totalweight of the polycarbonate composition of at least one salt prepared bythe reaction of one or more acidic phosphorus-containing compoundsselected from phosphorous acid, phosphoric acid and polyphosphoric acidwith one or more hinder light amine stabilizers of claim
 2. 4. Acomposition according to claim 3 wherein component B comprises about0.05 to about 0.15 weight percent based on the total weight of thepolycarbonate composition of at least one said salt wherein R₇ ishydrogen or alkyl and the ratio of the number of phosphorus atoms in theacidic phosphorous-containing compound to number of basic nitrogen atomsin the hindered amine light stabilizer compound is about 0.25 to about1.1.
 5. A polymer composition comprising: (A) at least onepolycarbonate; and (B) about 0.01 to about 0.25 weight percent based onthe total weight of the composition of at least one salt prepared by thereaction of phosphorous acid with one or more hindered amine lightstabilizers of the formulas:

Wherein R₁ and R₂ are independently selected from hydrogen,C₁-C₂₂-alkyl, substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substitutedC₃-C₈-cycloalkyl, heteroaryl, and aryl; R₃, R₄, R₅, and R₆ areindependently selected from hydrogen, C₁-C₂₂-alkyl, substitutedC₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substituted C₃-C₈-cycloalkyl,heteroaryl, aryl; R₇ is selected from hydrogen, —OR₆, C₁-C₂₂-alkyl,substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substitutedC₃-C₈-cycloalkyl; R₈ is selected from hydrogen; C₁-C₂₂-alkyl,substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substitutedC₃-C₈-cycloalkyl, heteroaryl, aryl, —Y₁—R₁ or a succinimido group havingthe formula

R₉ and R₁₀ are independently selected from hydrogen, C₁-C₂₂-alkyl,substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, and substitutedC₃-C₈-cycloalkyl; R₉ and R₁₀ may collectively represent a divalent groupforming a ring with the nitrogen atom to which they are attached, e.g.,morpholino, piperidino and the like; L₁ is a divalent linking groupselected from C₂-C₂₂-alkylene; —(CH₂CH₂—Y₁)₁₋₃—CH₂CH₂—;C₃-C₈-cycloalkylene; arylene; or —CO-L₂-OC—; L₂ is selected fromC₁-C₂₂-alkylene, arylene, —(CH₂CH₂—Y₁)₁₋₃—CH₂CH₂— andC₃-C₈-cycloalkylene; Y₁ is selected from —OC(O)—, —NHC(O)—, —O—, —S—,—N(R₁)—; Y₂ is selected from —O— or —N(R₁)—; Z is a positive integer ofup to about 20, preferably up to about 6; m1, is selected from 0 toabout 10; n1 is a positive integer selected from 2 to about 12; R₁₁, andR₁₂ are independently selected from hydrogen, C₁-C₂₂-alkyl, substitutedC₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substituted C₃-C₈-cycloalkyl,heteroaryl, aryl, and radical A wherein radical A is selected from thefollowing structures:

Radical A structures wherein * designates the position of attachment.wherein at least one of R₁ and R₁₂ is an A radical; and wherein theratio of the number of phosphorus atoms in the acidicphosphorus-containing compound to the number of basic nitrogen atoms inthe HALS is about 0.25 to about 2, preferably from about 0.5 to about1.1.
 6. A polymer composition comprising: (A) at least onepolycarbonate; and (B) about 0.01 to about 0.25 weight percent based onthe total weight of the composition of at least one salt prepared by thereaction of phosphorous acid with a hindered amine light stabilizerhaving the formula:

wherein: R₁ is independently selected from hydrogen, C₁-C₂₂-alkyl,substituted C₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substitutedC₃-C₈-cycloalkyl, heteroaryl, and aryl; R₃, R₄, R₅, and R₆ areindependently selected from hydrogen, C₁-C₂₂-alkyl, substitutedC₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, substituted C₃-C₈-cycloalkyl,heteroaryl, aryl; R₇ is selected from hydrogen or —C₁-C₂₂-alkyl; R₉ andR₁₀ are independently selected from hydrogen, C₁-C₂₂-alkyl, substitutedC₁-C₂₂-alkyl, C₃-C₈-cycloalkyl, and substituted C₃-C₈-cycloalkyl whereinat least one of R₉ and R₁₀ is a substituent other than hydrogen; R₉ andR₁₀ may collectively represent a divalent group forming a ring with thenitrogen atom to which they are attached: L₁ is a divalent linking groupselected from C₂-C₂₂-alkylene; —(CH₂CH₂—Y₁)₁₋₃—CH₂CH₂—;C₃-C₈-cycloalkylene; arylene; or —CO-L₂-OC—; and L₂ is selected fromC₁-C₂₂-alkylene, arylene, —(CH₂CH₂—Y₁)₁₋₃—CH₂CH₂— andC₃-C₈-cycloalkylene; Y₁ is selected from —OC(O)—, —NHC(O)—, —O—, —S—,—N(R₁)—; and Z is a positive integer of up to about
 6. 7. A compositionaccording to claim 6 wherein component (B) comprises about 0.05 to about0.15 weight percent based on the total weight of the composition of saidsalt wherein R₃=R₄=R₅=R₆=R₇=methyl; L₁ is hexamethylene; and (R₉)(R₁₀)N—collectively represent a morpholino group and the ratio of the number ofphosphorus atoms in the phosphorous acid to number of basic nitrogenatoms in the hindered amine light stabilizer is about 0.25 to about 1.1.8. A composition according to claim 7 wherein component (B) comprisesabout 0.05 to about 0.15 weight percent based on the total weight of thecomposition of at least one said salt wherein the ratio of the number ofphosphorus atoms in the phosphorous acid to number of basic nitrogenatoms in the hindered amine light stabilizer is about 0.25 to about 0.6.